Synchronization mechanism for pivot door thrust reversers

ABSTRACT

A thrust reverser includes a frame having a longitudinal axis, a first reverser door pivotally mounted to the frame, a second reverser door pivotally mounted to the frame, a crank pivotally mounted to the frame, a first link connecting the crank to the first reverser door, and a second link connecting the crank to the second reverser door. In various embodiments, both the first reverser door and the second reverser door are driven by a single actuator.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of, and claims priority to and thebenefit of, U.S. application Ser. No. 16/110,266, filed Aug. 23, 2018and titled “SYNCHRONIZATION MECHANISM FOR PIVOT DOOR THRUST REVERSERS,”which claims priority to, and the benefit of, U.S. ProvisionalApplication Ser. No. 62/577,075, filed Oct. 25, 2017 and titled“SYNCHRONIZATION MECHANISM ALLOWING SINGLE ACTUATOR—SMASA,” both ofwhich are incorporated herein by reference in their entirety for allpurposes.

FIELD

The present disclosure relates generally to aircraft thrust reversersused with gas turbine engines and, more particularly, to synchronizationmechanisms used with pivot door thrust reversers.

BACKGROUND

Turbofan gas turbine engines are known to include a fan section thatproduces a bypass airflow for providing the majority of enginepropulsion and a core engine section through which a core airflow iscompressed, mixed with fuel, combusted and expanded through a turbine todrive the fan section. In a mixed flow turbofan engine, the cool bypassairflow is ducted between a surrounding nacelle and an outer casing ofthe core engine section and mixed with a hot exhaust stream from thecore engine section prior to discharge from the engine nozzle in acombined or mixed exhaust stream. The surrounding nacelle may includethrust reversers capable of redirecting the bypass airflow from therearward direction to, at least partially, a forward direction thusproducing a rearward thrust that may serve to decelerate the forwardmotion of an aircraft and thereby assist braking the aircraft uponlanding. Pivot door thrust reversers may be used with turbofan gasturbine engines for aircraft, including for corporate or business jets.

SUMMARY

A thrust reverser is disclosed. In various embodiments, the thrustreverser includes a frame having a longitudinal axis, a first reverserdoor pivotally mounted to the frame, a second reverser door pivotallymounted to the first reverser door, a crank pivotally mounted to theframe, a first link connecting the crank to the first reverser door anda second link connecting the crank to the second reverser door. Invarious embodiments, the frame includes a first end and a second endspaced longitudinally from the first end and the first reverser door ispivotally mounted to the frame proximate the second end. In variousembodiments, the frame includes a central portion intermediate the firstend and the second end and the crank is pivotally mounted to the frameat a crank pivot point proximate the central portion. In variousembodiments, the crank includes an inner radial portion with respect tothe crank pivot point and an outer radial portion with respect to thecrank pivot point and the first link has a first end pivotally connectedto the inner radial portion. The second link may also have a first endpivotally connected to the outer radial portion.

In various embodiments, the first reverser door includes an aft end anda first offset panel positioned proximate the aft end and the firstoffset panel is pivotally mounted to the frame at a first panel pivotpoint. In various embodiments, the second reverser door includes an aftend and a second offset panel positioned proximate the aft end and thesecond offset panel is pivotally mounted to the first reverser door at asecond panel pivot point. In various embodiments, the crank is pivotallymounted to the frame at the crank pivot point positioned along thelongitudinal axis and the first panel pivot point is positioned on afirst side of the longitudinal axis. In various embodiments, the secondpanel pivot point is positioned on a second side of the longitudinalaxis opposite the first side.

In various embodiments, the frame comprises a side beam of a thrustreverser having a fore end and an aft end, the longitudinal axis runslongitudinally from the fore end of the side beam to the aft end of theside beam, and the first reverser door is a lower reverser door withrespect to the side beam. In various embodiments, the second reverserdoor is an upper reverser door with respect to the side beam, the firstpanel pivot point is spaced a first distance above the longitudinal axisand the second panel pivot point is spaced a second distance below thelongitudinal axis. In various embodiments, the frame includes a secondside beam spaced a lateral distance from the first side beam, and thethrust reverser further comprises a second crank pivotally mounted tothe second side beam, a third link connecting the second crank to thefirst reverser door and a fourth link connecting the second crank to thesecond reverser door.

In various embodiments, the thrust reverser includes an actuator thathas a first end connected to the frame and a second end connected to thefirst reverser door. In various embodiments, the frame further includesa bulkhead and the actuator is a linear actuator having a first endconnected to the bulkhead and a second end connected to the firstreverser door.

A pivot door thrust reverser is disclosed. The thrust reverser includesa frame having a central axis, a first side beam and a second side beam,the second side beam being positioned on an opposite side of the centralaxis from the first side beam, a first reverser door pivotally mountedto the first side beam and to the second side beam, a second reverserdoor pivotally mounted to the first reverser door, a first crankpivotally mounted to the first side beam at a first crank pivot point, afirst link connecting the first crank to the first reverser door and asecond link connecting the first crank to the second reverser door.

In various embodiments, the first side beam includes an aft end, thesecond side beam includes an aft end and the first reverser door ispivotally mounted to the frame proximate the aft end of the first sidebeam and proximate the aft end of the second side beam. In variousembodiments, the first reverser door includes a first side and a secondside, the second reverser door includes a first side and a second sideand the first side of the second reverser door is pivotally mounted tothe first side of the first reverser door and the second side of thesecond reverser door is pivotally mounted to the second side of thefirst reverser door.

In various embodiments, the first crank includes an inner radial portionwith respect to the first crank pivot point and an outer radial portionwith respect to the first crank pivot point and the first link has afirst end pivotally connected to the inner radial portion and the secondlink has a first end pivotally connected to the outer radial portion. Invarious embodiments, the thrust reverser further includes a second crankpivotally mounted to the second side beam at a second crank pivot point,a third link connecting the second crank to the first reverser door anda fourth link connecting the second crank to the second reverser door.In various embodiments, the second crank includes an inner radialportion with respect to the second crank pivot point and an outer radialportion with respect to the second crank pivot point and the third linkhas a first end pivotally connected to the inner radial portion and thefourth link has a first end pivotally connected to the outer radialportion. In various embodiments, the first link has a second endpivotally connected to the first side of the first reverser door and thesecond link has a second end pivotally connected to the first side ofthe second reverser door. In various embodiments, the third link has asecond end pivotally connected to the second side of the first reverserdoor and the fourth link has a second end pivotally connected to thesecond side of the second reverser door.

A pivot door thrust reverser is disclosed. In various embodiments, thethrust reverser includes a frame having a central axis, a forwardbulkhead, a first side beam extending aft of the forward bulkhead and asecond side beam extending aft of the forward bulkhead, the second sidebeam being positioned on an opposite side of the central axis from thefirst side beam, a lower reverser door pivotally mounted to the firstside beam and to the second side beam, an upper reverser door pivotallymounted to the lower reverser door, a first crank pivotally mounted tothe first side beam, a second crank pivotally mounted to the second sidebeam, a first link connecting the first crank to the lower reverserdoor, a second link connecting the first crank to the upper reverserdoor, a third link connecting the second crank to the lower reverserdoor, a fourth link connecting the second crank to the upper reverserdoor and an actuator having a first end connected to the frame and asecond end connected to the lower reverser door.

BRIEF DESCRIPTION OF THE DRAWINGS

The subject matter of the present disclosure is particularly pointed outand distinctly claimed in the concluding portion of the specification. Amore complete understanding of the present disclosure, however, may bestbe obtained by referring to the following detailed description andclaims in connection with the following drawings. While the drawingsillustrate various embodiments employing the principles describedherein, the drawings do not limit the scope of the claims.

FIG. 1 is a schematic view of a gas turbine engine, in accordance withvarious embodiments;

FIG. 2 is a schematic view of a stowed thrust reverser for a gas turbineengine, according to various embodiments;

FIGS. 3A and 3B are a schematic views of a deployed thrust reverser fora gas turbine engine, according to various embodiments;

FIGS. 4A, 4B, 4C and 4D are schematic views of a thrust reverser,according to various embodiments, illustrating a progression of stepsbetween stowed and deployed states; and

FIGS. 5A and 5B are schematic views of a thrust reverser, according tovarious embodiments, illustrating the thrust reverser in the stowed anddeployed states.

DETAILED DESCRIPTION

The following detailed description of various embodiments herein makesreference to the accompanying drawings, which show various embodimentsby way of illustration. While these various embodiments are described insufficient detail to enable those skilled in the art to practice thedisclosure, it should be understood that other embodiments may berealized and that changes may be made without departing from the scopeof the disclosure. Thus, the detailed description herein is presentedfor purposes of illustration only and not of limitation. Furthermore,any reference to singular includes plural embodiments, and any referenceto more than one component or step may include a singular embodiment orstep. Also, any reference to attached, fixed, connected, or the like mayinclude permanent, removable, temporary, partial, full or any otherpossible attachment option. Additionally, any reference to withoutcontact (or similar phrases) may also include reduced contact or minimalcontact. It should also be understood that unless specifically statedotherwise, references to “a,” “an” or “the” may include one or more thanone and that reference to an item in the singular may also include theitem in the plural. Further, all ranges may include upper and lowervalues and all ranges and ratio limits disclosed herein may be combined.

As used herein, a first component that is “radially outward” of a secondcomponent means that the first component is positioned at a greaterdistance away from a common axis than the second component. A firstcomponent that is “radially inward” of a second component means that thefirst component is positioned closer to the common axis than the secondcomponent. In the case of components that rotate circumferentially abouta common axis, a first component that is radially inward of a secondcomponent rotates through a circumferentially shorter path than thesecond component. As used herein, “distal” refers to a direction outwardor, generally, away from a reference component. As used herein,“proximal” or “proximate” refer to a direction inward or, generally,towards a reference component.

Referring now to the drawings, FIG. 1 schematically illustrates a gasturbine engine 100 of the turbofan variety. The gas turbine engine 100generally includes a fan section 102 and a core engine section 104,which includes a compressor section 106, a combustor section 108 and aturbine section 110. The fan section 102 drives air along a bypass flowpath B in a bypass duct 112 defined within a radially inner surface 115of a nacelle 114 and an outer casing 116 of the core engine section 104,while the compressor section 106 drives air along a core flow path C ofthe core engine section 104 for compression and communication into thecombustor section 108 and then expansion through the turbine section110.

The core engine section 104 may generally include a low speed spool anda high speed spool mounted for rotation about a central longitudinalaxis A. The low speed spool generally includes an inner shaft thatinterconnects a fan 118 within the fan section 102, a low pressurecompressor within the compressor section 106 and a low pressure turbinewithin the turbine section 110. The inner shaft may be connected to thefan 118 through a speed change mechanism or gear box to drive the fan118 at a lower rotational speed than the rotational speed of the lowspeed spool. The high speed spool generally includes an outer shaft thatinterconnects a high pressure compressor within the compressor section106 and a high pressure turbine within the turbine section 110. Acombustor is arranged in the combustor section 108 between the highpressure compressor and the high pressure turbine. The air passingthrough the bypass flow path B mixes with the combustion gases exitingthe core flow path C in a mixing section 122 positioned downstream ofthe core engine section 104 prior to discharge as a mixed exhaust stream120, which provides the thrust achieved by the gas turbine engine 100.

A thrust reverser 130 is mounted to the aft end of the gas turbineengine 100. The thrust reverser 130 includes a generally annular exhaustduct 132, which defines an outer boundary for discharging the mixedexhaust stream 120 when the thrust reverser 130 assumes a closed, stowedor retracted position, as illustrated in FIG. 1. The thrust reverser 130further includes an upper reverser door 134, a lower reverser door 136and a pair of opposing side beams 138, which may house actuatorcomponentry and connecting members used to open and close the upperreverser door 134 and lower reverser door 136. As discussed below,thrust reversal is affected by opening the upper reverser door 134 andthe lower reverser door 136 to direct all or a portion of the mixedexhaust stream 120 in a direction having an upstream component relativeto the central longitudinal axis A of the gas turbine engine 100. Themomentum of the upstream component of the mixed exhaust stream 120provides the reverse thrust used to decelerate an aircraft upon landing.

Referring now to FIG. 2, a side view of a thrust reverser 200 accordingto various embodiments is illustrated in the closed, stowed or retractedposition. The thrust reverser 200 includes an upper reverser door 202, alower reverser door 204, a pair of opposing side beams 206 (only one isshown) and an exhaust duct 208. In various embodiments, a cover 207 maybe incorporated into the opposing side beams 206 to affect anaerodynamic surface about an exterior of the thrust reverser 200. Asdescribed in more detail below, the pair of opposing side beams 206provide, or are components of, a frame 230 that may also include abulkhead 232. The frame 230 provides structural support for mountingcomponents associated with operating the thrust reverser 200 betweenstowed and deployed states or positions. In various embodiments, forexample, an actuator 210 may have a first end 211 connected to thebulkhead 232 and a second end (hidden) connected to an inner surface ofthe lower reverser door 204. As described in further detail below, thethrust reverser includes a pivot 212 that connects the upper reverserdoor 202 to the lower reverser door 204.

Still referring to FIG. 2, a central axis A is illustrated extendingthrough the thrust reverser 200. The central axis A may define a foreend or fore direction 240 of the thrust reverser 200 and an aft end oraft direction 242 of the thrust reverser 200. Various embodiments of thedisclosure may be described in relation to the central axis A. Forexample, the upper reverser door 202 may be considered positioned abovethe central axis A while the lower reverser door 204 may be consideredpositioned below the central axis A. Similarly, a port side beam 209 maybe considered positioned to the port or left side of the central axis A(looking in the fore direction 240) while a starboard side beam (hidden)may be considered positioned to the right or starboard side of thecentral axis A. More generally, however, reference to a first reverserdoor may generally refer to a reverser door positioned opposite a secondreverser door with respect to the central axis A, there being nopreferred up or down or side to side orientation, while reference to afirst side beam may generally refer to a side beam positioned opposite asecond side beam with respect to the central axis A. As used herein, afirst object being positioned opposite a second does not imply oneobject is a mirror image of the other or is positioned symmetrically tothe other, though such configurations or positioning are not excludedeither.

Referring now to FIGS. 3A and 3B, a schematic perspective view 300 a ofa thrust reverser 300 and a schematic side view 300 b of a thrustreverser 300 are shown, according to various embodiments, in the open ordeployed state or position. Similar to the foregoing description withreference to FIG. 2, the thrust reverser 300 includes a second or upperreverser door 302, a first or lower reverser door 304 and a pair ofopposing side beams 306 (only one is shown). The thrust reverser 300includes a frame 350 which, without loss of generality, may itselfcomprise, singularly or together, one or both of the pair of opposingside beams 306, a nozzle portion 314 and a bulkhead 352. A central axisA may extend through the thrust reverser 300 while, in variousembodiments, a longitudinal axis L may extend through one of the pair ofopposing side beams 306. Both the central axis A and the longitudinalaxis L may be considered to extend fore and aft with respect to a foredirection 340 and an aft direction 342.

Still referring to FIGS. 3A and 3B, the thrust reverser 300 includes afirst side beam 360. The first side beam 360 includes a longitudinalaxis L extending generally in fore and aft directions and has a first orfore end 362, a second or aft end 364 and a central portion 366intermediate the two ends. The first or lower reverser door 304 includesa fore end 368 and an aft end 370. The first or lower reverser door 304is generally arcuate in cross section and includes a first side 372 anda second side 374 that generally run fore and aft along the length ofthe reverser door. The second or upper reverser door 302 has similarcharacteristics, including fore and aft ends and a first side 376 and asecond side 378. The first or lower reverser door 304 is pivotallymounted to the first side beam 360 at a first pivot point 334. Invarious embodiments, the first pivot point 334 may comprise a pin or aspherical bearing. The first or lower reverser door 304 includes anoffset panel 380 that extends from the first side 372 of the first orlower reverser door 304 a distance sufficient to pivotally connect withthe first side beam 360 at the first pivot point 334. Referring brieflyto FIG. 3B, the first pivot point 334 is spaced a first offset distance382 from the longitudinal axis L. In various embodiments, the firstoffset distance 382 can be positive (e.g., above the longitudinal axisL) or negative (e.g., below the longitudinal axis L). The first or lowerreverser door 304 may further include an offset panel on the second side374 of the first or lower reverser door 304 that is pivotally connectedto a second side beam (hidden) in a manner similar to that justdescribed. In various embodiments, a first hinge-line 390 extendsthrough the first pivot point 334 on the first side 372 of the first orlower reverser door 304 and the pivotal connection on the second side374 of the first or lower reverser door 304. In various embodiments, thefirst hinge-line will extend in a direction perpendicular to the centralaxis A. In various embodiments, the pivotal connection on the secondside 374 of the first or lower reverser door 304 is laterally oppositethe first pivot point 334.

While the first or lower reverser door 304, as above described, ispivotally mounted to the first and second side beams, the second orupper reverser door 302, as described below, is pivotally mounted to thefirst or lower reverser door 304. The second or upper reverser door 302includes an offset panel 384 that extends from the first side 376 of thesecond or upper reverser door 302 a distance sufficient to pivotallyconnect with the first or lower reverser door 304 at a second pivotpoint 312. In various embodiments, the second pivot point 312 maycomprise a pin or a spherical bearing. The second pivot point 312extends through both the offset panel 384 of the second or upperreverser door 302 and the offset panel 380 of the first or lowerreverser door 304. The second or upper reverser door 302 may furtherinclude an offset panel on the second side 378 of the second or upperreverser door 302 that is pivotally connected to an offset panel on thesecond side 374 of the first or lower reverser door 304 in a mannersimilar to that just described. In various embodiments, a secondhinge-line 392 extends through the second pivot point 312 on the firstside 376 of the second or upper reverser door 302 and the pivotalconnection on the second side 378 of the second or upper reverser door302. In various embodiments, the second hinge-line will extend in adirection perpendicular to the central axis A. In various embodiments,the pivotal connection on the second side 378 of the second or upperreverser door 302 is laterally opposite the second pivot point 312. Invarious embodiments, the second hinge-line 392 may be fore or aft of thefirst hinge-line 390. In various embodiments, the first hinge-line 390may be parallel to the second hinge-line 392. In various embodiments,the first hinge-line 390 may be non-parallel to the second hinge-line392. In various embodiments, the first hinge-line 390 may be above thesecond hinge-line 392 (e.g., with respect to a vertical plane) and invarious embodiments the first hinge-line 390 may be below the secondhinge-line 392 (e.g., with respect to a vertical plane).

The above disclosure describes a thrust reverser 300 having a first orlower reverser door 304 that is pivotally mounted to first and secondside beams and a second or upper reverser door 302 that is pivotallymounted to the first or lower reverser door 304. In various embodiments,the structure of the various components of the pivot mechanismsdescribed above with respect to the first side 372 of the first or lowerreverser door 304 and the first side 376 of the second or upper reverserdoor 302 is symmetrically identical to the structure of the variouscomponents of the pivot mechanisms described with respect to the secondside 374 of the first or lower reverser door 304 and the second side 378of the second or upper reverser door 302. The following disclosuredescribes a linkage mechanism that enables the second or upper reverserdoor 302 to open and close in synchronization with the first or lowerreverser door 304, according to various embodiments.

Referring still to FIGS. 3A and 3B, a first crank 320 is pivotallydisposed on the first side beam 360 at a crank pivot point 322 proximatethe central portion 366 of the first side beam 360. A first link 324connects the first crank 320 to the first side 372 of the first or lowerreverser door 304. A second link 330 connects the first crank 320 to thefirst side 376 of the second or upper reverser door 302. In variousembodiments, the first crank 320 may be characterized by a radialdimension 395 (with respect to the crank pivot point 322) as having anouter radial portion and an inner radial portion, with the outer radialportion having a radial dimension greater than the inner radial portion.In various embodiments, the first link 324 has a first end pivotallyconnected to the inner radial portion of the first crank 320 at a firstpivot point 326 and a second end connected to the first side 372 of thefirst or lower reverser door 304 at a second pivot point 328. In variousembodiments, the second link 330 has a first end pivotally connected tothe outer radial portion of the first crank 320 at a first pivot point332 and a second end connected to the first side 376 of the second orupper reverser door 302 at a second pivot point 336.

In various embodiments, the thrust reverser 300 may include a secondcrank (hidden) pivotally mounted to a second side beam positionedopposite the first side beam 360. Similar to the above description, invarious embodiments, a third link (opposite the first link 324) may havea first end pivotally connected to an inner radial portion (with respectto a crank pivot point for the second crank) of the second crank at afirst pivot point and a second end connected to the second side 374 ofthe first or lower reverser door 304 at a second pivot point. Similarly,a fourth link (opposite the second link 330) may have a first endpivotally connected to an outer radial portion (with respect to thecrank pivot point for the second crank) of the second crank at a firstpivot point and a second end connected to the second side 378 of thesecond or upper reverser door 302 at a second pivot point. In variousembodiments, the second crank and associated linkage is opposite to andsymmetric with the first crank 320 and its associated linkage, includingthe first link 324 and the second link 330 and the various connectingpivot points, as described above.

The thrust reverser 300 may further include an actuator configured toopen and close the first or lower reverser door 304. In variousembodiments, a linear actuator 310 is employed to open and close thefirst or lower reverser door 304. The linear actuator 310 may include afirst end 311 pivotally connected to the bulkhead 352 and a second end313 pivotally connected to the first or lower reverser door 304. Invarious embodiments, the linear actuator 310 is centrally positionedbetween the first side beam 360 and the second side beam and the secondend 313 of the linear actuator 310 is connected to a center portion ofthe inner surface of the first or lower reverser door 304. In variousembodiments, the actuator, e.g., the linear actuator 310, is positionedoff-center, such as adjacent the first side beam 360 or the second sidebeam. In various embodiments, multiple actuators may be used to affectopening and closing of the first and second reverser doors.

Referring now to FIGS. 4A, 4B, 4C and 4D, operation of a thrust reverser400 is illustrated and described in accordance with various embodiments.Referring to FIG. 4A, a thrust reverser 400 is illustrated in a closedor stowed state 400 a. Similar to the above description, the thrustreverser 400 includes a first or lower reverser door 404, a second orupper reverser door 402 and a frame, including a first side beam 460.The first or lower reverser door 404 includes an offset panel 480 thatis pivotally mounted to the first side beam 460 at a first pivot point434 and the second or upper reverser door 402 includes an offset panel484 that is pivotally mounted to the first or lower reverser door 404 ata second pivot point 412. A longitudinal axis L runs in fore and aftdirections along the first side beam 460. A first crank 420 is pivotallymounted to the first side beam 460 at a crank pivot point 422 positionedalong the longitudinal axis L. While described as being pivotallymounted along the longitudinal axis L, in various embodiments, the firstcrank 420 may be mounted in other locations, either along the first sidebeam 460 or, more generally, the frame. A first link 424 connects thefirst crank 420 to the first or lower reverser door 404 and a secondlink 430 connects the first crank 420 to the second or upper reverserdoor 402.

In various embodiments, the first pivot point 434, where the first orlower reverser door 404 is pivotally connected to the first side beam460, is positioned on an upper or first side of the longitudinal axis Land spaced a first distance 482 from the longitudinal axis L. In variousembodiments, the second pivot point 412, where the second or upperreverser door 402 is pivotally connected to the first or lower reverserdoor 404, is positioned on a lower or second side of the longitudinalaxis L and spaced a second distance 486 from the longitudinal axis L. Invarious embodiments, one or both of the first distance 482 and thesecond distance 486 are greater than zero. In various embodiments, oneor both of the first distance 482 and the second distance 486 may begreater than or less than zero, meaning the corresponding hinge-linesmay be on the same side of the longitudinal axis L or on opposite sidesof the longitudinal axis L.

As described above, in various embodiments, the thrust reverser 400 mayinclude a second crank (hidden) pivotally mounted to a second side beampositioned opposite the first side beam 460. A third link (opposite thefirst link 424) may have a first end pivotally connected to an innerradial portion of the second crank and a second end connected to thefirst or lower reverser door 404 and a fourth link (opposite the secondlink 430) may have a first end pivotally connected to the second crankand a second end connected to the second or upper reverser door 402. Invarious embodiments, the second crank and associated linkage is oppositeto and symmetric with the first crank 420 and its associated linkage,including the first link 424 and the second link 430 and the variousconnecting pivot points, as described above.

Referring still to FIGS. 4A, 4B, 4C and 4D, various kinematic positionsof the thrust reverser are illustrated as the thrust reverser opens froma closed or stowed state 400 a, to a first partially deployed state 400b, to a second partially deployed state 400 c and, finally, to a fullydeployed state 400 d. Starting from the stowed state 400 a, an actuator410 urges the first or lower reverser door 404 to pivot in ananti-clockwise manner about the first pivot point 434. As the first orlower reverser door 404 pivots, the second end of the first link 424follows the first or lower reverser door 404, thereby urging the firstcrank 420 to pivot about the first side beam 460. As the first crank 420pivots, the second end of the second link 430 urges the second or upperreverser door 402 to pivot with respect to the first or lower reverserdoor 404 at the second pivot point 412. The process continues througheach of the stages illustrated in FIGS. 4A-D. To stow the reverser doorsfrom a deployed state or position, the process is reversed.

The disclosure provides a synchronized linkage for opening and stowingfirst and second reverser doors. The first link 424 and the second link430 couple the first crank 420 to the first or lower reverser door 404and the second or upper reverser door 402, the second pivot point 412couples the second or upper reverser door 402 to the first or lowerreverser door 404 and the first pivot point 434 couples both reverserdoors to the first side beam 460. While the disclosure provides anactuator 410 having a first end 411 connected to a bulkhead and a secondend connected to the first or lower reverser door 404, it should beapparent that the actuator may be configured otherwise, such as to openand close the second or upper reverser door 402 or, alternatively, torotate the first crank 420.

Referring now to FIGS. 5A and 5B, a thrust reverser 500 is illustratedand described, in accordance with various embodiments, in a closed orstowed state 500 a and in an open or deployed state 500 b. Similar tothe above description, the thrust reverser 500 includes a first reverserdoor 504, a second reverser door 502 and a frame, including a first sidebeam 560. The first reverser door 504 includes a tab or offset panel 580that is pivotally mounted to the first side beam 560 at a first pivotpoint 534 and the second reverser door 502 includes a tab or offsetpanel 584 that is pivotally mounted to the first side beam 560 at asecond pivot point 512. A longitudinal axis L runs in fore and aftdirections along the first side beam 560. A first crank 520 is pivotallymounted to the first side beam 560 at a first crank pivot point 522positioned along the longitudinal axis L. While described as beingpivotally mounted along the longitudinal axis L, in various embodiments,the first crank 520 may be mounted in other locations, either along thefirst side beam 560, above or below the longitudinal axis L, or, moregenerally, anywhere on the frame. A first link 524 connects the firstcrank 520 to the first reverser door 504 at a first door-link pivotpoint 525 and a second link 530 connects the first crank 520 to thesecond reverser door 502 at a second door-link pivot point 531.

In various embodiments, the first pivot point 534, where the firstreverser door 504 is pivotally connected to the first side beam 560, ispositioned on a first side of the longitudinal axis L and spaced a firstdistance 582 from the longitudinal axis L. In various embodiments, thesecond pivot point 512, where the second reverser door 502 is pivotallyconnected to the first side beam 560, is positioned on a second side ofthe longitudinal axis L and spaced a second distance 586 from thelongitudinal axis L. In various embodiments, one or both of the firstdistance 582 and the second distance 586 are greater than zero. Invarious embodiments, one or both of the first distance 582 and thesecond distance 586 may be greater than or less than zero, meaning thecorresponding hinge-lines may be on the same side of the longitudinalaxis L or on opposite sides of the longitudinal axis L.

As described above, in various embodiments, the thrust reverser 500 mayinclude a second crank (hidden) pivotally mounted to a second side beampositioned opposite the first side beam 560. A third link (opposite thefirst link 524) may have a first end pivotally connected to the secondcrank and a second end connected to the first reverser door 504 and afourth link (opposite the second link 530) may have a first endpivotally connected to the second crank and a second end connected tothe second reverser door 502. In various embodiments, the second crankand associated linkage is opposite to and symmetric with the first crank520 and its associated linkage, including the first link 524 and thesecond link 530 and the various connecting pivot points, as describedabove.

The disclosure provides a synchronized linkage for opening and stowingfirst and second reverser doors hinged to a frame or one or more sidebeams of a frame. The first link 524 and the second link 530 couple thefirst crank 520 to the first reverser door 504 and the second reverserdoor 502, the second pivot point 512 couples the second reverser door502 to the first side beam 560 and the first pivot point 534 couples thefirst reverser door 504 to the first side beam 560. While the disclosureprovides an actuator 510 having a first end 511 connected to a bulkheadand a second end 513 connected to the first reverser door 504, it shouldbe apparent the actuator may be configured otherwise, such as to openand close the second reverser door 502 or, alternatively, to rotate thefirst crank 520.

Benefits, other advantages, and solutions to problems have beendescribed herein with regard to specific embodiments. Furthermore, theconnecting lines shown in the various figures contained herein areintended to represent exemplary functional relationships and/or physicalcouplings between the various elements. It should be noted that manyalternative or additional functional relationships or physicalconnections may be present in a practical system. However, the benefits,advantages, solutions to problems, and any elements that may cause anybenefit, advantage, or solution to occur or become more pronounced arenot to be construed as critical, required, or essential features orelements of the disclosure. The scope of the disclosure is accordinglyto be limited by nothing other than the appended claims, in whichreference to an element in the singular is not intended to mean “one andonly one” unless explicitly so stated, but rather “one or more.”Moreover, where a phrase similar to “at least one of A, B, or C” is usedin the claims, it is intended that the phrase be interpreted to meanthat A alone may be present in an embodiment, B alone may be present inan embodiment, C alone may be present in an embodiment, or that anycombination of the elements A, B and C may be present in a singleembodiment; for example, A and B, A and C, B and C, or A and B and C.Different cross-hatching is used throughout the figures to denotedifferent parts but not necessarily to denote the same or differentmaterials.

Systems, methods and apparatus are provided herein. In the detaileddescription herein, references to “one embodiment,” “an embodiment,”“various embodiments,” etc., indicate that the embodiment described mayinclude a particular feature, structure, or characteristic, but everyembodiment may not necessarily include the particular feature,structure, or characteristic. Moreover, such phrases are not necessarilyreferring to the same embodiment. Further, when a particular feature,structure, or characteristic is described in connection with anembodiment, it is submitted that it is within the knowledge of oneskilled in the art to affect such feature, structure, or characteristicin connection with other embodiments whether or not explicitlydescribed. After reading the description, it will be apparent to oneskilled in the relevant art(s) how to implement the disclosure inalternative embodiments.

Furthermore, no element, component, or method step in the presentdisclosure is intended to be dedicated to the public regardless ofwhether the element, component, or method step is explicitly recited inthe claims. No claim element herein is to be construed under theprovisions of 35 U.S.C. 112(f) unless the element is expressly recitedusing the phrase “means for.” As used herein, the terms “comprises”,“comprising”, or any other variation thereof, are intended to cover anon-exclusive inclusion, such that a process, method, article, orapparatus that comprises a list of elements does not include only thoseelements but may include other elements not expressly listed or inherentto such process, method, article, or apparatus.

What is claimed:
 1. A thrust reverser, comprising: a frame having alongitudinal axis; a first reverser door pivotally mounted to the frame;a second reverser door pivotally mounted to the frame; a first crankpivotally mounted to the frame, the first crank having an outer radialportion and an inner radial portion with respect to a radial dimensionextending from a crank pivot point; a first link directly connecting theinner radial portion of the first crank to the first reverser door; anda second link directly connecting the outer radial portion of the firstcrank to the second reverser door.
 2. The thrust reverser of claim 1,wherein the frame includes a first end, a second end spacedlongitudinally from the first end and a central portion intermediate thefirst end and the second end and wherein the first crank is pivotallymounted to the frame at the crank pivot point proximate the centralportion.
 3. The thrust reverser of claim 2, wherein the first reverserdoor is pivotally mounted to the frame proximate the second end of theframe.
 4. The thrust reverser of claim 3, wherein the first reverserdoor includes a first reverser door aft end and a first offset panelpositioned proximate the first reverser door aft end and wherein thefirst offset panel is pivotally mounted to the frame at a first offsetpanel pivot point.
 5. The thrust reverser of claim 4, wherein the secondreverser door includes a second reverser door aft end and a secondoffset panel positioned proximate the second reverser door aft end andwherein the second offset panel is pivotally mounted to the frame at asecond offset panel pivot point.
 6. The thrust reverser of claim 5,wherein the first crank is pivotally mounted to the frame at the crankpivot point, the crank pivot point extending perpendicularly through thelongitudinal axis, and wherein the first offset panel pivot point ispositioned on a first side of the longitudinal axis.
 7. The thrustreverser of claim 6, wherein the second offset panel pivot point ispositioned on a second side of the longitudinal axis opposite the firstside.
 8. The thrust reverser of claim 7, wherein the frame comprises afirst side beam having a first side beam fore end and a first side beamaft end, wherein the longitudinal axis extends longitudinally from thefirst side beam fore end to the first side beam aft end, wherein thefirst reverser door is a lower reverser door with respect to the firstside beam, wherein the second reverser door is an upper reverser doorwith respect to the first side beam, wherein the first offset panelpivot point is spaced a first distance below the longitudinal axis andwherein the second offset panel pivot point is spaced a second distanceabove the longitudinal axis.
 9. The thrust reverser of claim 8, whereinthe frame includes a second side beam spaced a lateral distance from thefirst side beam, and wherein the thrust reverser further comprises asecond crank pivotally mounted to the second side beam, a third linkconnecting the second crank to the first reverser door and a fourth linkconnecting the second crank to the second reverser door.
 10. The thrustreverser of claim 9, further comprising an actuator having a first endconnected to the frame and a second end connected to the first reverserdoor.
 11. The thrust reverser of claim 10, wherein the frame furthercomprises a bulkhead and wherein the first end is connected to thebulkhead.
 12. A pivot door thrust reverser, comprising: a frame having acentral axis, a first side beam and a second side beam, the second sidebeam positioned on an opposite side of the central axis from the firstside beam; a first reverser door pivotally mounted to the first sidebeam and to the second side beam; a second reverser door pivotallymounted to the first side beam and to the second side beam; a firstcrank pivotally mounted to the first side beam at a first crank pivotpoint, the first crank having a first crank outer radial portion and afirst crank inner radial portion with respect to a radial dimensionextending from the first crank pivot point; a first link directlyconnecting the first crank inner radial portion of the first crank tothe first reverser door; and a second link directly connecting the firstcrank outer radial portion of the first crank to the second reverserdoor.
 13. The thrust reverser of claim 12, wherein the first side beamincludes a first side beam aft end, wherein the second side beamincludes a second side beam aft end and wherein the first reverser dooris pivotally mounted to the frame proximate the first side beam aft endof the first side beam and proximate the second side beam aft end of thesecond side beam.
 14. The thrust reverser of claim 13, wherein thesecond reverser door is pivotally mounted to the frame proximate thefirst side beam aft end of the first side beam and proximate the secondside beam aft end of the second side beam.
 15. The thrust reverser ofclaim 14, further comprising a second crank pivotally mounted to thesecond side beam at a second crank pivot point, a third link connectingthe second crank to the first reverser door and a fourth link connectingthe second crank to the second reverser door, wherein the second crankincludes a second crank inner radial portion with respect to the secondcrank pivot point and a second crank outer radial portion with respectto the second crank pivot point and wherein the third link has a firstend pivotally connected to the second crank inner radial portion and asecond end pivotally connected to the first reverser door and the fourthlink has a first end pivotally connected to the second crank outerradial portion and a second end pivotally connected to the secondreverser door.
 16. A pivot door thrust reverser, comprising: a framehaving a central axis, a forward bulkhead, a first side beam extendingaft of the forward bulkhead and a second side beam extending aft of theforward bulkhead, the second side beam positioned on an opposite side ofthe central axis from the first side beam; a first reverser doorpivotally mounted to the first side beam and to the second side beam; asecond reverser door pivotally mounted to the first side beam and to thesecond side beam; a first crank pivotally mounted to the first side beamat a first crank pivot point, the first crank having an outer radialportion and an inner radial portion with respect to a radial dimensionextending from the first crank pivot point; a second crank pivotallymounted to the second side beam; a first link directly connecting theinner radial portion of the first crank to the first reverser door; asecond link directly connecting the outer radial portion of the firstcrank to the second reverser door; a third link directly connecting thesecond crank to the first reverser door; a fourth link directlyconnecting the second crank to the second reverser door; and an actuatorhaving a first end connected to the frame and a second end connected tothe first reverser door.